fix: personalización logo/color por contribuyente en vez de tenant

- Agrega getCustomizationContribuyente, uploadLogoContribuyente,
  updateColorContribuyente en contribuyente-facturapi.service.ts
- Agrega controllers per-contribuyente en facturacion.controller.ts
- Agrega rutas GET/POST/PUT /contribuyentes/:id/facturapi/customization|logo|color
- Modifica CustomizationSection para recibir contribuyenteId, usar endpoints
  per-contribuyente, y corrige useState mal aplicado a useEffect
- Backend y frontend buildeados y deployados

apps/api/src/services/contribuyente-facturapi.service.ts

@@ -542,3 +542,66 @@ async function ensureOrgLegalForEmit(
   const payload = await buildLegalPayload(contrib, chosenTaxSystem, currentLegal);
   await putOrgLegal(orgId, payload);
 }
+
+// ── Personalización (logo, color) per-contribuyente ──
+
+export async function getCustomizationContribuyente(
+  pool: Pool,
+  contribuyenteId: string,
+): Promise<{ logoUrl?: string; color?: string } | null> {
+  const { rows } = await pool.query<{ facturapi_org_id: string }>(
+    'SELECT facturapi_org_id FROM facturapi_orgs WHERE contribuyente_id = $1 AND active = true',
+    [contribuyenteId],
+  );
+  if (rows.length === 0) return null;
+
+  const userClient = getUserClient();
+  try {
+    const org = await userClient.organizations.retrieve(rows[0].facturapi_org_id);
+    return {
+      logoUrl: org.customization?.has_logo ? (org.logo_url ?? undefined) : undefined,
+      color: org.customization?.color || undefined,
+    };
+  } catch { return null; }
+}
+
+export async function uploadLogoContribuyente(
+  pool: Pool,
+  contribuyenteId: string,
+  logoBase64: string,
+): Promise<{ success: boolean; message: string }> {
+  const { rows } = await pool.query<{ facturapi_org_id: string }>(
+    'SELECT facturapi_org_id FROM facturapi_orgs WHERE contribuyente_id = $1 AND active = true',
+    [contribuyenteId],
+  );
+  if (rows.length === 0) throw new Error('Organización no configurada');
+
+  const userClient = getUserClient();
+  try {
+    const buffer = Buffer.from(logoBase64, 'base64');
+    await userClient.organizations.uploadLogo(rows[0].facturapi_org_id, buffer);
+    return { success: true, message: 'Logo subido correctamente' };
+  } catch (error: any) {
+    return { success: false, message: error.message || 'Error al subir logo' };
+  }
+}
+
+export async function updateColorContribuyente(
+  pool: Pool,
+  contribuyenteId: string,
+  color: string,
+): Promise<{ success: boolean; message: string }> {
+  const { rows } = await pool.query<{ facturapi_org_id: string }>(
+    'SELECT facturapi_org_id FROM facturapi_orgs WHERE contribuyente_id = $1 AND active = true',
+    [contribuyenteId],
+  );
+  if (rows.length === 0) throw new Error('Organización no configurada');
+
+  const userClient = getUserClient();
+  try {
+    await userClient.organizations.updateCustomization(rows[0].facturapi_org_id, { color });
+    return { success: true, message: 'Color actualizado correctamente' };
+  } catch (error: any) {
+    return { success: false, message: error.message || 'Error al actualizar color' };
+  }
+}